PROJECT SUMMARY Whereas men's intellectual successes are often described as resulting from intrinsic talent, women's intellectual successes are more often credited to their dedicated efforts (Swim & Sanna, 1996). These gender- stereotyped attributions of success are particularly pronounced when evaluating others' achievements in male- dominated science, technology, engineering, and math (STEM) fields. That is, whereas men's scientific accomplishments are often ascribed to natural talents, women's similar successes are more often attributed to their dedication. Children's math achievements are also subject to these stereotype-driven evaluations: both parents and teachers reporting that girls must put forth more effort than boys to attain the same level of math proficiency by first grade (e.g., Frome & Eccles, 1998; Robinson-Cimpian et al., 2014). These findings align with evidence that women believe they must exert greater effort than their peers to achieve similar levels of success in male-dominated disciplines, a belief that diminishes women's educational pursuits in STEM fields (Smith et al., 2013). Thus, attributing girls' math achievements to their efforts may reduce girls' learning outcomes in math-related domains, ultimately constraining their educational and professional aspirations from an early age. To address this possibility, the proposed research will examine the development of gender- stereotyped achievement attributions and their relation to girls' attitudes and motivation toward novel math activities. The goal of this research is to contribute insight into early-emerging psychological processes that impede girls' learning in math. The proposed research will be the first to investigate the origins of gender-stereotyped attributions of success during childhood and characterize their relations to girls' attitudes towards math-related educational activities. This research will consist of three studies. Study 1 will examine the extent to which children differentially attribute the academic success of females and males throughout childhood. Study 2 will assess whether girls expect to devote greater effort than boys to succeeding in math activities, and if so, whether greater effort expectations reduce girls' motivation to engage in such activities. Study 3 will test whether emphasizing that effort, rather than ability, is critical to success of all children will increase girls' interests and confidence in pursuing novel math activities. Together, these studies will (1) offer insight into the development of gender- stereotyped achievement attributions and (2) provide a theoretically plausible and practically significant framework from which to develop interventions aimed at enhancing girls' math learning outcomes.